Vinegar has many uses, from natural remedies to powerful cleaning agent. Here is an example of a guy who used vinegar in order to remove the hard water buildup. He soaked a T-shirt in vinegar and applied it on the area which needed cleaning. He allowed it to act for an hour and then he removed the dirt deposits easily, using a sponge.
However, the use of vinegar as a cleaning agent is limited in certain areas. According to a study published in the Journal of Environmental Health, vinegar has powerful ability to eliminate microbial contamination, but he cannot remove soil as effectively as other similar cleaning agents.
Baking soda has the ability to remove soil but it cannot eliminate microbial contamination. The study found the commercial cleaners as most effective, but they contain strong chemical compounds, such as bleach.
This guy proved that natural cleaning agents can also be effective in cleaning a number of surfaces. He uses 5% vinegar and he warns that any higher concentration can damage the metal.